This is a continued search for methods to provide long term (one week) blood oxygenation using membrane oxygenators in animals and patients suffering potentially reversable pulmonary insufficiency or Respiratory Distress Syndrome. Specific areas of interest include: 1) Miniaturization and sensitization of pump control for use in Neonate RDS. 2) Development of Expanded Polytetrafluoroethylene (PTFE or Gore- Tex) membranes for use in existing silicone membrane devices. Testing of these Gore-Tex membrane oxygenators in hypoxic animals for prolonged periods of partial by-pass and if feasible for total cardio-pulmonary by-pass. 3) Design and development of tubed Expanded PTFE oxygenators with blood flowing over oxygen filled tubes of this highly gas permeable material. 4) Investigation of use of Expanded PTFE tubes as common duct, tracheal and venous replacement.